This invention relates to vertical shaft windmills.
The windmill is a well-known method of harnessing naturally occurring forces. It has been suggested as a possible alternative to other sources of energy which are becoming more scarce or less readily accessible. Windmills may be thought of as being of two basic types, those with horizontal shafts and those with vertical shafts. Many vertical shaft windmills are disclosed in the prior art, for example, U.S. Pat. Nos. 250,806 issued Dec. 13, 1881 to Hamel; 588,572 issued Aug. 24, 1897 to Hardaway; 863,715 issued Aug. 20, 1907 to Higby et al.; 864,789 issued Sept. 3, 1907 to Kickbush; 1,234,405 issued July 24, 1917 to Solomon; and 1,382,591 issued June 21, 1921 to Ackermann.
The present invention deals with an improved arrangement for stationary wind directing and concentrating vanes and rotors for vertical shaft windmills. In accordance with the invention, a windmill comprises a vertical shaft having a rotor fixedly connected thereto. The rotor comprises a series of vertically extending, equally peripherally spaced trough-shaped wind scoops, each of which has leading and following edges joined respectively to the following and leading edges of adjacent wind scoops to form a generally cylindrical scoop assembly, the peripheral width of the open face of each scoop defining a length of the arc of the generally cylindrical assembly. Wind is directed toward and concentrated upon, the open faces of the scoops by a series of stationary wind directing and concentrating vanes which are peripherally spaced about the generally cylindrical scoop assembly in a generally tangential fashion. The proximal ends of the stationary vanes adjacent the scoop assembly are concentrically cylindrically shaped and approximate the curvature of the cylinder defined by rotation of the scoop assembly. The length of arc represented by the stationary proximal vane ends adjacent the rotor is greater than the arc length of the wind scoops. Wind is thus prevented from escaping from a given scoop as that scoop moves behind the cylindrically shaped proximal end of a stationary vane.
In accordance with a preferred embodiment of the invention, such windmills are constructed one upon another and joined by a common shaft to form a composite windmill.